1. Field of the Invention
The present invention relates to an actuator which is displaceable by a very small amount by using a piezoelectric element; and a transporting apparatus, a movable apparatus, and a device which include the actuator.
2. Description of the Related Art
A transporting apparatus which includes a transporting roller and a drive motor which drives the transporting roller has been hitherto used for transporting a paper to be recorded in a recording apparatus. However, in recent years, a technology for applying a piezoelectric actuator, having a piezoelectric element made of a ceramics material such as lead zirconate titanate (PZT), to a variety of usages has been studied, and in particular, a technology for transporting an object to be transported by using a deformation which is developed when a voltage is applied to the piezoelectric element has been proposed. For example, a piezoelectric actuator which has a plurality of piezoelectric elements each including a substrate in the form of a plate, piezoelectric elements provided to both surfaces of the substrate, and a plurality of electrodes formed on surfaces of the piezoelectric elements, is described in Japanese Patent Application Laid-open Publication No. 2003-111456. This piezoelectric actuator is structured such that a front tip portion of the substrate is caused to be deformed due to bending deformation of the piezoelectric element, and an object to be transported is transported by being moved by a very small amount in a longitudinal direction of the object by a ciliary movement of a plurality of substrates arranged in a circumferential direction of the object to be transported which is cylindrical or tubular in shape.